The potential use of synthetic polymeric materials in the building construction industry has long been recognized. The low cost, ease of handling, and desirable maintenance characteristics, make plastics obvious materials for use in the manufacture of building components such as coatings, panels, and trim. One problem which has held back the progress of polymer compositions in this area is that they are generally quite flammable and, as thin coatings, they provide little fire protection to substrates on which they are laminated. Furthermore, the combustion of organic polymers usually generates billows of malodorous smoke which not only hampers firefighting efforts but also turns even small fires into major problems. Additionally, the "kindling" effect of the burning polymers often elevates the flame temperature, thereby igniting articles which would not have been effected. Another problem is that most polymers cure slowly, require addition of heat to cure, or release dangerous solvents during curing, all of which make manufacture difficult. In the case of pre-polymerized materials the mechanical fabrication requires very expensive molds and the like. One of the most desirable types of polymers are polyacrylates. Attempts have been made to reduce the combustibility of these materials by adding "flame-proofing agents" such as chlorinated paraffin wax, tricresyl phosphate and tris (2,3-dichloropropyl) phosphate (see British Patent No. 1,157,436 to Norman Wilkins, 1969). Such a prior art material, as seen in Example 2, has a Flame Spread Rating (F.S.R.) of 100 as determined by the Steiner Tunnel Test (A.S.T.M. E84) (using an equivalent 2 ft. tunnel). An F.S.R. of 25 or below would be far more desirable. These and other difficulties experienced with the prior art compositions have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a liquid polymerizable composition which, after curing, is fire resistant.
A further object is to provide a bulk molding compound from which can be molded fire-resistant articles that will not necessarily be attached to any substrate.
Another object of this invention is the provision of a liquid polymerizable composition from which fire-resistant articles can be fabricated.
A further object of the present invention is the provision of a polymeric composition which can be used as a coating not only to render inexpensive substrates (such as construction-grade plywood) more attractive, but also protect the substrate from both moisture and fire.
It is another object of the instant invention to provide a polymeric composition which is non-burning and self-expanding, thereby forming a thermal barrier when exposed to intense heat.
A still further object of the invention is the provision of a liquid polymerizable composition which is applied to a substrate in liquid form, adhers well, increases in viscosity quickly, and cures at room temperature.
It is a further object of the invention to provide a polymeric composition which gives off little or no smoke when exposed to flame and has little objectionable smell when exposed to flames or when used in manufacturing a product.
A further object of the invention is the provision of a building material that changes from liquid to solid without the release of solvent or other objectionable volatile component.
A still further object is to provide a fire-resistant gel coat on a reinforced fiberglass laminate having load-bearing capabilities, such as building components, boats, car and truck bodies and the like.
With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of steps and the details of the composition hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.